1. Technical Field
The present disclosure relates to an indicator detecting device, such as an indicator detecting device used with a tablet terminal and a protective cover therefor.
2. Description of the Related Art
Tablet terminals, which have become significantly popular in recent years, are generally formed into a thin plate shape having a touch panel exposed in the front surface. Therefore, protective covers for protecting the touch panel have become popular together with the tablet terminals. One example of such a protective cover is disclosed in Japanese Patent Laid-open No. 2012-043182 and Japanese Patent Laid-open No. 2014-132372.
Furthermore, an example in which an input device such as a keyboard and a mouse is attached as an external device to a tablet terminal is known. For example, a product made by connecting an external keyboard to a tablet terminal is disclosed in a product introduction site of Surface, which is a registered trademark of Microsoft Corporation.
Typically, there are needs of consumers to carry out pen input on the basis of an indicator detection system different from the indicator detection system of a touch panel of a tablet terminal while using the tablet terminal. For example, there is a need to carry out pen input on the basis of the electro-magnetic resonance technology (EMR) system or the electrostatic (ES) system, which enables input with higher accuracy than the capacitive system, while using a tablet terminal having a touch panel of the capacitive system.
It is conceivable that an indicator detecting device (digitizer) compatible with the EMR system or the ES system is connected as one of external input devices to a tablet terminal in order to meet such a need. This makes it possible to use the indicator detecting device compatible with the EMR system or the ES system as an input device of the tablet terminal.
However, with this configuration, the user needs to carry both the tablet terminal and the indicator detecting device with the user, which is inconvenient for the user. Furthermore, also in use, the indicator detecting device and the tablet terminal are lined up in the direction of the line of sight of the user and are used. Therefore, there is a problem that it is difficult to use the tablet terminal in the case in which there is not sufficient space, such as the case in which the tablet terminal is used on a seat table in a bullet train, for example.
In contrast, for example according to a configuration of the product discussed above, a keyboard may be formed on a surface of a protective cover. Thus, the above-described problem does not occur if the keyboard is replaced by an indicator detecting device. However, this configuration requires the dedicated protective cover and therefore is not realistic generally, aside perhaps from the case in which the protective cover and the tablet terminal are integrally sold by the same company. Furthermore, originally the product discussed above is a product whose largest advantage is that the product has a hardware keyboard although being a tablet terminal, and equipping the product with an indicator detecting device instead of the keyboard is not realistic.